Cryptogenic organizing pneumonia

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at November 28, 2016
StartDiseasesCryptogenic organizing pneumonia

Cryptogenic organizing pneumonia, or COP is a rare disease where the very small airways and alveoli of the lungs are obstructed from scarring and inflammation. The alveoli are the tiny sacs at the ends of the always where carbon dioxide and oxygen are exchanged in the lungs. When examined, the inflammation looks like tiny swirls of inflamed tissue that clog these structures. That these swirls seem to be organized gives the condition part of its name. COP used to be called bronchiolitis obliterans organizing pneumonia, but most doctors no longer use the term. Another name for COP is Epler’s pneumonia.


Definition & Facts

Cryptogenic organizing pneumonia is a type of idiopathic interstitial pneumonia. It is found all over the world. Idiopathic means that know one knows what causes the disease, while interstitial means the disease invades the small spaces inside the lung.

COP doesn’t seem to be an actual infection. Cryptogenic organizing pneumonia affects men and women equally. The usual onset of the disorder is between 50 and 60 years old. Its prevalence has been estimated to be six to seven out of every 100,000. About two thirds of patients recover from their episodes of COP. The other third continue to have symptoms that progress or persist, but even they can be treated.

Symptoms & Complaints

The symptoms of COP vary from individual to individual, but they usually involve:

Other rare symptoms are night sweats, wheezing, chest pain, and pain in the joints. Sometimes, doctors or even the patient can hear rattling or crackling sounds coming from the lungs. These symptoms tend to develop slowly, over weeks or months, though in a rare form of cryptogenic organizing pneumonia the symptoms come on suddenly and send the patient into respiratory failure after a few days.


A person is diagnosed with cryptogenic organizing pneumonia when doctors can’t find anything else that could have caused the pneumonia, including bacteria, viruses, or other pathogens. COP is not the result of treatment for cancer, blood cancers, diseases of the connective tissues or other disorders which can cause similar symptoms.

As of 2016, doctors and medical researchers have found no genetic factors or genetic mutations that can lead to COP. There’s no sign that it can be passed down from parent to child or that it is found in some families and not in others.

Diagnosis & Tests

To diagnose COP, the doctor does a physical examination and takes the patient’s medical history. The doctor will ask many questions about the patient’s employment, living situation, hobbies and recent travels outside of the country. The doctor then tests the patient for more traditional forms of pneumonia. These include chest X-rays, blood tests, blood cultures, a pulse oximetry, and tests to check the patient’s sputum and pleural fluid, which is fluid found in the space between the membranes that line the lung and the chest cavity.

If these tests come back negative, the doctor might order a computed tomography (CT) scan, which uses X-rays to take “slices” of the patient’s chest area to create three-dimensional images of the lungs. The doctor may also order a lung biopsy, where a small tissue sample is removed from the lung through a bronchoscope and then studied under a microscope.

One type of test that helps to diagnose cryptogenic organizing pneumonia is high-resolution computed tomography or HRCT. If the disease is present, the image may reveal what looks like ground glass in the chest cavity. This is a sign of many lung diseases, including COP.

Doctors also need to rule out the patient’s being exposed to drugs, whether they are street drugs such as cocaine, prescribed antibiotics, or anti-seizure drugs. They also need to rule out autoimmune diseases such as rheumatoid arthritis and lupus, and transplants that involve the bone marrow, lungs, kidneys, or stem cells.

Treatment & Therapy

COP is most often treated with corticosteroids or glucocorticoids which are types of corticosteroids. These are substances that are very much like the hormones made by the adrenal glands. Their function is to reduce inflammation and help the body handle stress. They can be given orally or intravenously if the patient needs to be hospitalized.

Because corticosteroids can have serious side effects, including unintended weight gain, facial swelling, mental disturbances, confusion, ulcers, and vision problems, they are used for as short of a time as practicable. The most commonly used corticosteroid used to treat cryptogenic organizing pneumonia is prednisone, which is used to treat a host of disorders from allergies to cancer.

If the corticosteroids don’t help with the cryptogenic organizing pneumonia, the doctor may prescribe cytotoxic drugs. These drugs kill rapidly dividing cells and are often use in chemotherapy. Because COP is not caused by bacteria, antibiotics do not work against it. Other drugs used to combat cryptogenic organizing pneumonia are cyclophosphamide and erythromycin. In exceedingly rare cases, the only option to treat a severe case of COP is a lung transplant.

Prevention & Prophylaxis

Since doctors do not know what causes cryptogenic organizing pneumonia, there is no sure way to prevent it. However, corticosteroids are very good at treating the disease, and the patient often feels better within a few days. However, they must take the drug as it is prescribed and not skip doses or stop taking their medicine when they begin to feel well.

Some patients can also ward off or lessen the severity of recurring cryptogenic organizing pneumonia if they get a yearly flu shot and a shot that offers protection from the pneumococcus bacteria. If a patient has another episode of COP, it is important that they seek medical attention and have follow-up tests. Fortunately, even a recurring bout of cryptogenic organizing pneumonia tends to respond well to corticosteroid treatment.